Superficial venous thrombosis (SVT) of the lower extremities still deserves our attention because there is no evidence-based agreement about its diagnosis and treatment. SVT must be primarily classified in three main categories: 1) SVT in healthy veins; 2) SVT in varicose veins and 3) other kinds of SVT. Clinical diagnosis of SVT is always evident but it must be differentiated from limphangiitis that is an infectious disease of the soft tissues (its diagnosis is also clinically evident and assumes an underlying limphoedema – do not forget Stemmer’s sign !) and from deep venous thrombosis (swelling of the leg without any sign of phlogosis as “rubor/calor/tumor/dolor”). Proximal extension of SVT is conversely NOT clinically evident because what we can perceive with our touch is not the cranial limit of SVT but only the limit of the collateral vein before its confluence into the greater or lesser (small) saphenous veins. TVS’ proximal extension in the saphenous trunks can only be revealed by Colour Duplex (CD) investigation because these veins run far from the skin protected by the duplication of the superficial fascia and no sign of phlogosis can be seen on the skin. Proximal extension of SVT into the deep veins may even evolve into pulmonary embolism or in, sudden onset, retrograde DVT. This is obviously true in case of SVT in varicose veins. SVT of healthy veins is often more difficult to define because the only clinical sign is represented by pain. Palpation is not easy in obese patients and CD is needed to achieve or to confirm our clinical suspicion. The meaning of SVT in varicose and in healthy veins is quite different: SVT of varicose veins represents mostly an evolutive pattern of the varicose disease while SVT of healthy veins is always to be considered an indirect sign of an underlying disease, especially if it is a “migrating thrombophlebitis”. The differential diagnosis with the intriguing Mondor’s disease is always clinical because of its “iron thread” (string) presentation without any phlogistic skin appearance. Other kinds of SVT (traumatic, infectious, of the upper extremities etc.) and current therapy will also be considered.